CNN reported the development concerning the official, Robert Malley, on Thursday, quoting anonymous sources.
“I have been informed that my security clearance is under review. I have not been provided any further information, but I expect the investigation to be resolved favorably and soon,” Malley told Reuters.
“In the meantime, I am on leave,” he added.
Earlier, US State Department spokesman Matt Miller said Malley was on leave but did not say why or for how long, announcing that his deputy, Abram Paley, was filling in on an acting basis.
Several American officials, including former President Donald Trump, incumbent President Joe Biden, and former secretary of state Hillary Clinton have invoked investigations over their unprofessional or even suspicious handling of classified information and documents.
Malley was part of the American negotiating team that partook in the talks that led to the conclusion of a 2015 deal between world countries, including Washington, and Tehran.
The deal enabled the removal of some sanctions against Iran, which, in turn, volunteered to change some aspects of its peaceful nuclear energy program.
Trump, however, left the deal in 2018, and returned the sanctions.
Malley was appointed as the US’s special envoy for Iran soon after Joe Biden took over as the US president.
He has been part of Biden’s team that has been negotiating the potential revival of the agreement, which is officially known as the Joint Comprehensive Plan of Action (JCPOA).
